1. Field of the Invention
This invention pertains to shielded plug and receptacle connector assemblies, and in particular to shielded receptacle assemblies which are mounted in an aperture of a conductive panel.
2. Brief Description of the Prior Art
Many electronic circuits which are used to transmit signals are enclosed in metallic shielding for protection against the effects of electromagnetic radiation, electromagnetic interference (EMI), and the special category of radio frequency interference (RFI). There is an increasing need for separable electrical connectors which preserve the shielding properties of these circuits so as to not disturb the transmitted signal. In order to provide effective shielding, a connector system must provide a means for coupling the shields to a neutral ground potential and directing the interfering signals to ground.
Frequently, separable electrical connection is required at a housing wall, such as an electrically conductive wall of an electrical chassis. The possibility therefore arises to conveniently connect a connector shield to a conductive chassis wall which is grouned.
One such arrangement is provided in U.S. Pat. No. 3,922,056 issued to Murawski et al., on Nov. 25, 1975. In this arrangement, a receptacle member, mounted in the chassis wall, is completely surrounded by a metallic shield. The metallic shield is electrically connected to the chassis wall by a pair of generally L-shaped spring finger members, wherein one leg of the "L" is secured to the wall, and the other leg of the "L" wipes against the receptacle shield as it is inserted through the wall.
In U.S. Pat. No. 3,366,918 issued to F. W. Johnson, et al., on Jan. 30, 1968, a folded metal gasket provides a shell-to-shell-to-shelf RFI shield spring which is attached to a plug member mounted in the aperture of a conductive panel. The spring includes a number of outwardly directed fingers which are compressed by a metallic female socket, so that socket engages the plug member.
In yet another patent, U.S. Pat. No. 4,386,814 issued June 7, 1983 to John Asick, a kit is provided for converting an aperture of a conductive panel, into a shielded pin receptacle. The kit includes a unitary ground plane spring having a first set of fingers which engage the conductive panel, and a second set of fingers which project into the interior opening of a dielectric housing. The ground plane spring is trapped between the panel and the housing when the two are joined together. The second set of fingers wipe across the outside surface of a shielded plug-like connector which is inserted through the conductive panel and ground plane spring, being received within the dielectric housing. The latter arrangement, although providing a ready adaptation of existing equipment, requires a certain amount of time for a skilled operator to complete the kit conversion process. Also, a reliable grounding connection to the panel should be maintained, even if the panel or the housing should become warped. An integral, continuous ground plane spring may not provide the shape conformance required. Further, the conversion kit of U.S. Pat. No. 4,386,814 does not lend itself to automated assembly line fabrication procedures.